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Workshop => Engine and Bottom End => Topic started by: evaneyeball on February 16, 2020, 04:26:48 PM
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so i am going to be powder coating my engine cases a anodized red and i want my cylinder to be a flat black and the head to be the same color as the cases and ive heard that you cant powder coat a cylinder or head because it will get too hot. and im doing the powder coating on my own so its not like i can just ask the guy thats powder coating them because im doing it. and so can i powder coat them or do i have to do something like cerakoate.
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Same say powder coating cases is ok to do others say not to. Same with powder coating cylinders and heads. I’ve never had engine parts powder coated. I’m ok with rattle cans for the cases and a blasted/dull look for the cylinder and head. I think the concern is the heat in the top end....but it’s water cooled. Now as far as cases I’d say the concern is warpage and damaged bearing bores. I’m not a metallurgist nor a degreed engineer.
Joe
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I always paint the cases and cylinder/head. For the head and cylinder I use valspar plastikote rebuilders finish. It looks pretty good.
(https://thumbs2.imagebam.com/26/f3/6b/b90ff81334317836.jpg) (http://www.imagebam.com/image/b90ff81334317836)
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My builder (Pete @ Hybrid Engineering) strongly suggests that you do not powder coat cases. The heat can soften the aluminum and your main bearing bores will get loose. The cases were heat treated after casting by Honda. When you heat them over a certain temperature for a extended period it will anneal the aluminum. That can cause a big time failure. But! I have seen a ton of atv and motorcycle engine cases running around that were powder coated. I just choose paint.
Loren
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i think i will powder coat all the parts because if i cant use those colors it ruins the whole build.
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the cases and head will be the red on the water pump cover and the cylinder will be the black on the clutch cover. the color dosent really show in the pitures and so i had to use a filter on them to get the color to show better. it does look alot better in person
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My builder (Pete @ Hybrid Engineering) strongly suggests that you do not powder coat cases. The heat can soften the aluminum and your main bearing bores will get loose. The cases were heat treated after casting by Honda. When you heat them over a certain temperature for a extended period it will anneal the aluminum. That can cause a big time failure. But! I have seen a ton of atv and motorcycle engine cases running around that were powder coated. I just choose paint.
Loren
The above is very true!
I cannot count the number of times customers have had the structural integrity of aluminum parts ruined because they had them powered coated. Any time an aluminum part is raised over 300 deg. F the temper of aluminum starts to change.....the higher the temperature above 300 deg F...the faster the temper clocks ticks. Most of the powders coats require over 350 deg F to cure.
I do not recommend Powder Coating any aluminum parts, unless your are building a museum Queen and do not care about the strength, and thermal aspects of your engine parts.
I want my customers engines to get rid of as much of the waste heat as possible without having to depend entirely on the radiator. The cooling system actually consists of all of the external surfaces of the engine cases, cylinder, head, radiator, and hoses.
Paint is a thermal barrier or better know as an insulator. Powder coat paint is a better insulator than conventional paint because it is much thicker. Polishing a surface will have a similar effect as painting a surface. Polishing/painting a surface reduces the amount of heat that can be radiated off hot engines surfaces. The emmisive power of a sandblasted aluminum surface is almost 5 times higher than that of a polished aluminum surface. The emmisive power of a powder coated surface is much less than that of a polished surface. The emmisive power is a number that engineers use to compare the amount of heat that can be radiated from the surface of different materials with different surface textures.
In summary:
The following list will show the type of surface or surface treatment that will radiate the most heat. Number 1 will radiate the most heat and 6 the least amount of heat.
1. Sandblasted or heavily oxidized
2. Machined surface
3. Polished surface
4. Painted
5. Polished Chrome plated surface
6. Powdered coated
Numbers 3 and 4 could trade places depending upon the type of paint and thickness
Do everything you can to help reduce the amount of heat your radiator has to dissipate. Your cylinder and head probably have at least 50 times more surface area than those finned aluminum gadgets that many guys insert into their radiator hose in an attempt to make their engines run cooler.
Polishing and paint makes things look a lot nicer and easier to keep clean. The big question is: Do you want to keep your engine components as cool as possible or build a Museum Queen?
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My builder (Pete @ Hybrid Engineering) strongly suggests that you do not powder coat cases. The heat can soften the aluminum and your main bearing bores will get loose. The cases were heat treated after casting by Honda. When you heat them over a certain temperature for a extended period it will anneal the aluminum. That can cause a big time failure. But! I have seen a ton of atv and motorcycle engine cases running around that were powder coated. I just choose paint.
Loren
This & this. Just paint or polish.
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i checked and have an oversized radiator with bigger hoses,moving a lot more coolant than stock wich should cool everything alot better. and this thing will be babied it will be a sand princess. i mainly do jumps and sand trails. actually im pretty sure arlan told me to powder coat the cases. so i think im just going to powdercoat. plus its pretty easy for me to powder coat the cylinder because i do it all in my shop.
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I knew there was a reason why I like the look of raw aluminum & Mr. Hall just validated that in great detail. Thank you sir!
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Thank you Mr Hall. Your contributions are appreciated.
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OEM paint on cases
PJ1 high temp rattle can on cylinder
Still has the rough casting texture.
I leave the boot rub marks on the stator cover to show I actually ride it.
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i think you might be missing something to ride it starts with c and ends with hain.
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Ha ha. Good eye.
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i think you might be missing something to ride it starts with c and ends with hain.
Haha I was writing something along these lines but you beat me to it.
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right as i was typing broken1 replied and it wouldent let me post it but is that frame gusseted
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Looks like it has the Pumashine gusset kit.
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Yes. Pumashine kit.
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I need to order a few gusset kits
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i checked and have an oversized radiator with bigger hoses,moving a lot more coolant than stock wich should cool everything alot better and this thing will be babied. ..........
The water pump RPM is what moves or determines the amount of coolant moving thru the cooling system. The efficiency of the radiator is what determines how much heat is removed as the air passes through the radiator core. The fin density between the tubes and the number of tubes in the first row ( the row the experiences the coolest air entering the radiator) is what determines the radiators efficiency.
It has been my experience that the Chinese core material that is being used by most of the custom radiator manufacturers is not as efficient per square inch as the core material that was used on the original Honda radiators. If this is true with your "big radiator", your big radiator may need many more square inches of surface area to give equal cooling to a stock radiator that is in good condition.
Don't baby it too much. Radiators do not work well when you are going slow and not forcing a lot of air through the radiator. The 30-30 rule applies to most bikes that do not have cooling fans. The 30-30 rule is: the bikes speed needs to be above 30 MPH for about 30 seconds out of every minute to keep it cool when you are working the engine hard in the lower gears.
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Great information. Thanks Jerry
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how much of a temperature difference is there between the powder coating and the rattle can in the cylinder when running
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i checked and have an oversized radiator with bigger hoses,moving a lot more coolant than stock wich should cool everything alot better. and this thing will be babied it will be a sand princess. i mainly do jumps and sand trails. actually im pretty sure arlan told me to powder coat the cases. so i think im just going to powdercoat. plus its pretty easy for me to powder coat the cylinder because i do it all in my shop.
One of the hardest things growing up is knowing when you're getting good advice. I ruined my first set of cases after powder coating. Not too many hours later, two of my transmission bearings were loose in the bore. it's anecdotal, but I have no other known reason that's as likely to account for the widening bore holes. The cases are now my mock set for scribing port timing... Jerry Hall consumes and creates scientific data and has a deep physics background. You should take his advice. It's just not worth the risk. Rustoleum satin black is a really close match to OE black. Duplicolor Storm Gray for 86-7.
The size of your hoses probably don't matter so is not a reason to thik you can afford added heat retention. The tightest restriction in the coolant system is going to be the rate of flow, at best. You can attach your water pump to a drinking straw, then into a sewer pipe back to your water pump, It's only going to flow as much as the drinking straw allows, not the sewer pipe. I grew up in Glamis. Sand is one of the highest drag, engine heating surfaces you can ride on.
If you're a hands on guy and have a bead blaster, do the cylinder and head with glass beads. It will shine up the aluminum without reducing emissivity too badly. Take good advice. People don't like to keep seing it wasted. They stop giving it for free or reserve it for a different population.
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Great advice on this forum... and don't worry about matuus, he's not even a real person lol
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just talked to led and he said that he recommends powder coating engine cases.
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Where's @Pumashine's thread on that puma he painted metallic silver?